The acute dissection of a blood vessel wall can threaten a patient's life, especially in (1) acute dissection of wall of the coronary arteries, as a complication of angioplasty, and (2) in acute dissecting aneurysm of the aorta. In the former case, the flap of the intima inhibits the distal flow of blood, resulting in myocardial infarction. To treat this complication, the patient is operated urgently for coronary artery bypass surgery, which is associated with high perioperative mortality. Adjunctively and mainly as a "bridge" to the operating theatre, certain types of balloon catheters (autoperfusion catheters) are used. These catheters, through special apertures, permit an amount of blood to flow to the periphery, while supporting the flap against the vessel wall during the time they are situated in the area of the lesion. Another way to treat the acute dissection of the coronary arteries, without surgical intervention, is the permanent placement of endoprostheses (stents), made of metal in most of the cases, which in their expanded form support the flap and permit the flow of blood through the lumen. Stents are, however, associated with high acute thrombosis (4-20%) and restenosis (approximately 30%) rate. As far as the acute dissection of the aorta is concerned, the only relatively effective way of treatment is the surgical placement of a graft. However, such intervention is associated with high perioperative mortality, especially if the aneurysm is extensive or if it involves vital vessels.